MnO₂ Nanorods Embedded Reduced Graphene Oxide Nanocomposite with Ultrahigh Specific Capacitance and Excellent Cyclic Stability for High Performance Supercapacitors

Abstract

Excellent cycling stability along with a high specific capacitance of the electrode material is the primary requirement for supercapacitor (SC) in recent years. Exceptionally simple and cost-effective solution process is employed for the first time to prepare [Formula: see text]-MnO 2 /rGO composites, in which KMnO 4 content varies from (2[Formula: see text]mg, 4[Formula: see text]mg, 6[Formula: see text]mg and 8[Formula: see text]mg). The morphological analysis showed that [Formula: see text]-MnO 2 /rGO composites possess nanorod like morphology and were fully covered with rGO sheet. Among all composites, the sample with 6[Formula: see text]mg content of KMnO 4 denoted as [Formula: see text]-MnO 2 /rGO composite (S–3) showed excellent supercapacitive performance with a specific capacitance of 720[Formula: see text]F/g at a current density of 4 A g[Formula: see text] with excellent cycling stability of 93% after 2000 cycles. Furthermore, these nanocomposites showed excellent supercapacitive properties with specific capacitances of 720–498 F/g at the current density of 4 A g[Formula: see text] with cycling stabilities of 71%, 68% and 60%, respectively.